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Topic Review (Newest First)

11-07-2012 08:34 PM

vinniekq2

the worst part of vortec heads is the exhaust flow ratio is terrible.The intake flows 230 plus cfm...If you can get the exhaust to flow 185 cfm then your engine will make very good power.You need a flow bench to check your flow.

11-07-2012 05:23 PM

cobalt327

Quote:

Originally Posted by Jkingof956

ok i will check that. also do i need to do some cleanup like deburring around the intake valve seat? just like i did to the exhaust ports or do i leave it as is and just do the exhaust ports?

There's usually an area (seen in the image below) that needs attention on all the valves (click on image below for a page on head porting). Just don't get into the valve seat or the machined angles approaching just above and below the seat if the heads have been given a three angle valve job.

Research where the short turn radius is located and leave that area alone.

Good luck.

11-07-2012 03:16 PM

Jkingof956

Quote:

Originally Posted by cobalt327

Like I said- only remove any mismatch as seen if you were looking from the intake runner towards the cylinder head intake port. If there's cylinder head showing where the manifold meets the head, remove it. Don't worry about the mismatch going from the head towards the intake manifold.

ok i will check that. also do i need to do some cleanup like deburring around the intake valve seat? just like i did to the exhaust ports or do i leave it as is and just do the exhaust ports?

11-06-2012 10:18 PM

cobalt327

Quote:

Originally Posted by Jkingof956

so now that I messed up on port maching with gasket am I now am forced to gasket matched my intake manifold???

Like I said- only remove any mismatch as seen if you were looking from the intake runner towards the cylinder head intake port. If there's cylinder head showing where the manifold meets the head, remove it. Don't worry about the mismatch going from the head towards the intake manifold.

11-06-2012 06:53 PM

Jkingof956

Quote:

Originally Posted by ap72

no. just leave it as is.

oh ok i will do so thanks for the help

11-06-2012 05:59 PM

ap72

Quote:

Originally Posted by Jkingof956

so now that I messed up on port maching with gasket am I now am forced to gasket matched my intake manifold???

no. just leave it as is.

11-06-2012 05:53 PM

Jkingof956

Quote:

Originally Posted by cobalt327

They're fine- you're worrying too much, me thinks.

In the future what you can look to remove is any "overhang" into the port that is seen as viewed from the intake into the head's intake port. You don't want any of the head's intake flange obstructing the flow from the intake manifold's port into the head. If there's a mismatch as seen looking from the head back into the intake, this can be ignored. Actually, some say this mismatch can reduce reversion in some cases.

It takes careful measurements to get this precise- to the point of mocking up the heads on the block then mounting the intake using templates (or intake gaskets) as references.

What can happen when doing a simple gasket matching of the ports, is a bulge is created where the head and intake meet. Someone here referred to it as looking like a snake that ate a rabbit, or something like that. This is to be avoided! What will happen is the flow slows as the cross section enlarges and this can cause turbulence and reduced flow.

You can do a search for port matching as opposed to gasket matching for more details.

so now that I messed up on port maching with gasket am I now am forced to gasket matched my intake manifold???

11-05-2012 10:09 PM

cobalt327

Quote:

Originally Posted by Jkingof956

so guys based on the pics i posted what do you all think will it hurt what has been done?

They're fine- you're worrying too much, me thinks.

In the future what you can look to remove is any "overhang" into the port that is seen as viewed from the intake into the head's intake port. You don't want any of the head's intake flange obstructing the flow from the intake manifold's port into the head. If there's a mismatch as seen looking from the head back into the intake, this can be ignored. Actually, some say this mismatch can reduce reversion in some cases.

It takes careful measurements to get this precise- to the point of mocking up the heads on the block then mounting the intake using templates (or intake gaskets) as references.

What can happen when doing a simple gasket matching of the ports, is a bulge is created where the head and intake meet. Someone here referred to it as looking like a snake that ate a rabbit, or something like that. This is to be avoided! What will happen is the flow slows as the cross section enlarges and this can cause turbulence and reduced flow.

You can do a search for port matching as opposed to gasket matching for more details.

11-05-2012 09:37 PM

Jkingof956

so guys based on the pics i posted what do you all think will it hurt what has been done?

11-05-2012 09:24 PM

BraveLil305

Quote:

Originally Posted by Jkingof956

i knew this already but i was just curious on cleaning up the inside casting marks not porting or reshaping

I'm picking up what you're laying down

11-05-2012 08:41 PM

ap72

Quote:

Originally Posted by BraveLil305

Porting vortec heads will only gain you a couple more HP. They were made to flow as much as possible from the factory already. They did a good job making them you're not gonna improve much on what they've already done.

A good port job can pick up 30cfm... that can be something significant to some people.

11-05-2012 08:19 PM

Jkingof956

Quote:

Originally Posted by BraveLil305

Porting vortec heads will only gain you a couple more HP. They were made to flow as much as possible from the factory already. They did a good job making them you're not gonna improve much on what they've already done.

i knew this already but i was just curious on cleaning up the inside casting marks not porting or reshaping

11-05-2012 08:11 PM

BraveLil305

Porting vortec heads will only gain you a couple more HP. They were made to flow as much as possible from the factory already. They did a good job making them you're not gonna improve much on what they've already done.

11-05-2012 08:09 PM

Jkingof956

this is the port matching in one head:

[IMG][/IMG]

and other head port matched:

stock exhaust port:

cleaned up exhaust port:

11-05-2012 08:04 PM

Jkingof956

thanks guys for the info, am uploading pics so you guys can see if they are messed up or still good to go...

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